To determine the prevalence and the 3-months incidence of SARS-CoV-2 in cancer patients (Part A).

To evaluate the Covid-19 disease-specific mortality rate in cancer patients treated by hydroxychloroquine and azithromycin (Part B).

Inclusion Criteria:

• All types of locally advanced and metastatic malignancy
• Male/female participants
• Age>18 y.o.
• Signed informed consent for participation in the study
• No restriction on Eastern Cooperative Oncology Group (ECOG)/World Health Organization (WHO) Performance Status
• Subject should not have received a prior systemic anti-viral treatment for Covid19 disease.

Exclusion Criteria:

• Patients with known hypersensitivity to hydroxychloroquine or chloroquine, azithromycin, erythromycin, or any other macrolide, ketolide or any of the excipients of the hydroxychloroquine and/or azithromycin-based specialty used.
• Severe hepatic impairment and patients with severe cholestasis.
• Patients with renal insufficiency with creatinine clearance < 40 mL/min.
• Combinations of drugs contraindicated in accordance with the approvals of the specialties used.
• Patients currently treated with Tamoxifen
• Patients already treated by hydroxychloroquine or azithromycin for Covid19 disease or currently treated with other antiviral drugs against coronavirus.
• Patients with known contra-indication to treatment with the study drug, including retinopathy, G6PD deficiency, QT prolongation and severe hepato-cellular insufficiency.
• Patients post allogeneic hematopoietic stem cell transplantation are eligible to the Part B treatments but the potential toxic effects of hydroxychloroquin and azithromycin on hematopoietic stem cells should be taken into consideration by prescribers.
• Pregnant or breastfeeding women. Women of childbearing potential (WOCBP, as defined in appendix 2) should have a negative urine or serum pregnancy test within 72 hours prior to receiving the first dose of study medication. If the urine test is positive or cannot be confirmed as negative, a serum pregnancy test will be required.